1. Field of the Invention
The invention relates to an image reading apparatus, and a copying machine and a compound machine provided with the same.
2. Description of Related Art
When two-side images on an original are to be read at a time, the two sides are scanned at a time by image reading sensors having photoelectric transferring means disposed on the front side and back side, respectively, of the original, but in Japanese Patent Application Laid-Open No. 11-69086, there is proposed an apparatus for reading the two sides of an original substantially at a time. Also, in Japanese Patent No. 2928449, there is proposed an apparatus provided with two CCD reduction optical system reading means on the opposite sides of an original feed path and for reading the two sides of a moving original substantially at a time.
The apparatus of Japanese Patent Application Laid-Open No. 11-69086 does not have means for effecting the detection of the position of the original when the original is conveyed to image reading means and therefore, it is difficult to start the scanning by the two image reading means in conformity with the arrival position of the leading edge of the original. Therefore, the read image may become a defective image having a blank space which is not the image of the original on the leading edge or the trailing edge thereof, or delayed in reading timing.
Also, in the apparatus of Japanese Patent No. 2928449, the image reading means opposed to each other are proximate to each other and therefore, lights from respective light sources may enter sensors on opposite sides and cause the read image to deteriorate.